Vat Polymerization Additive Manufacturing

Additive manufacturing has often been used for complex, low volume parts. But adoption is increasing with the ability to produce more complex parts by designing products specifically for additive manufacturing and improving the technology and process.  Costs are also being reduced through higher quality, reliability and stability of the process as well as faster production speeds. In vat polymerization systems—including stereolithography (SLA) and digital light processing (DLP)—a UV laser constructs an object in a vat of a liquid photopolymer resin by curing microfine layers of the resin.

MKS Solutions for Vat Polymerization Additive Manufacturing

Challenges in Vat Polymerization MKS Solutions
Maximize Speed / Reduce Process Time High repetition rate UV lasers with fast rise times
Deliver high-resolution finished parts UV lasers with high beam quality (M2 factor)
Optics for manipulation of UV light
High precision opto-mechanics and motion control
Reduce cost Beam profilers and sensors to ensure beam quality
Q-switched lasers

Your Partner for Additive Manufacturing

  • 50+ years and thousands of alignment systems for optical applications
  • Long-term partner to additive manufacturing companies
  • Full range of products: lasers, optics, opto-mechanics, beam profilers, sensors, positioners
    • Proven performance
    • Product availability
  • Ability to scale with you
  • Global corporation and presence

Lasers

Optics

Opto-Mechanics

Beam Analysis
  • DPSS Q-switched lasers
  • UV lasers
  • Nanosecond lasers
  • UV optics
  • High-energy optics
  • Precision lens assemblies
  • Mirror mounts
  • Lens positioners
  • Integrated optical, opto-mechanical and electronic subassemblies
  • High power laser thermal sensors
  • High power beam profilers
  • Laser power/energy meters

Lasers

Criteria for Selecting Lasers

  • Wavelength (primarily UV)
  • Power (up to a few Watts)
  • Repetition Rate (tens to hundreds of kHz)
  • Beam Quality (M2 as close to 1)
  • Rise Time
  • Long Term Stability

Explorer® One™ Compact Nanosecond Lasers

Explorer One is ideal for vat polymerization. It is the most compact UV nanosecond laser in its class and features output powers up to a few Watts and nanosecond pulse widths. Combined with typical rise times of about 90% maximum power within 1 to 2 pulses, very fast scans are achievable in a vat polymerization system. High resolution scans are ensured with the laser's excellent beam quality and power stability.

Explorer One Explorer One XP Explorer One HP
Wavelength UV
Power 800 mW 2 W >4 or >6 W
Pulse Width <10 ns <12 or <15 ns
Repetition Rates Single shot to 200 kHz Single shot to 500 kHz Single shot to 200 or 500kHz
M2 <1.3, TEM00
Stability <2%
Other Features Very compact, lightweight air-cooled designs
Fast rise times
Thousands of hours in the field

HighQ-2™ Ultracompact Air-Cooled Femtosecond Lasers

HighQ-2 is ideal for two-photon polymerization (2PP), a technique based on the same principle of stereolithography (SLA), which can fabricate 3D microstructures suspended inside the liquid or gel without the need for a support structure. But unlike traditional SLA, which utilizes UV ns lasers, 2PP requires ultrashort pulse lasers, typically with visible to NIR wavelengths. HighQ-2 is an ultracompact, fs laser that delivers exceptional results for 2PP. Its high peak power, highly focusable Gaussian spatial beam profile and very high stability enable micron- and sub-micron-scale precision..

HighQ-2
HighQ-2™
Wavelength IR Green
Peak Power >80 kW >35 kW
Average Power >1.5 W >0.65 W
Pulse Width <250 fs
Repetition Rates 63 MHz
M2 <1.15, TEM00
Power Stability <1% rms (100 hours)
<0.5% rms (12 hours)
Other Features Ultra-compact
Air-cooled
High uptime
Low cost of ownership

Optics

For the vat polymerization lasers required, you will likely be operating around 355 nm UV. There are broadband and laser line optics available, but since you’ll know specifically which wavelength you’ll have, we recommend using laser line optics when possible because they’re optimized for a specific wavelength and will perform better than a broadband optic.

Criteria for Selecting Optics

  • Wavelength (primarily UV)
  • Laser Damage Threshold
    • Substrate Material
    • Coating
  • Reflectivity/Transmission
  • Size and Shape

Complex Optics & Optical Assemblies

MKS has a very experienced team of lens designers, opto-mechanical engineers and physicists that specialize in optical design and development. We are more than just a supplier of optical components – MKS can be your partner to deliver optical solutions for your needs. We can provide high precision optical assemblies, for example, lens assemblies. We can also build complete integrated solutions of optics, opto-mechanics and electronics, such as a system to shape beams and quickly change focus and spot size.

We specialize in the design of thin film coatings for laser optics whether it be reflective, anti-reflective, partially reflective, high power and other types. Vat polymerization typically uses UV wavelengths, such as 355 nm, but we also have much experience with coatings down to 193 nanometers. In addition to providing traditional optical shapes and coatings, MKS can also produce complex optical shapes, such as freeform optics, highly convex or concave optics, truncated optics and lightweight optics. We also have the capability of placing multiple coating types on a single optical component.

MKS will design a custom solution to meet your application's requirements, and we can handle build-to-print or build-to-specs. With our world class manufacturing capabilities, we are able to scale quantities as needed and also provide cost-effective high volume production.

High-Energy Laser Mirrors

High-energy laser mirrors optimized for 355-nm offer very high reflectivity and damage thresholds, and standard broadband metallic mirrors offer a more economic option for good performance and value over very broad spectral ranges.

High-Energy Laser Mirrors Broadband Metallic Mirrors
Wavelength 355 nm 250-600 nm
CW Damage Threshold 3 kW/cm2 100 W/cm2
Pulsed Damage Threshold 3.5 J/cm2 @ 10 ns, 20 Hz
Reflectivity Rs > 99.7%
Rp > 99%
>90%
Diameter 1 and 2 in. 0.5 to 8 in.
Substrate Material UV Grade Fused Silica Borofloat 33, Zerodur
Angle of Incidence 45° Insensitive to polarization and AOI

High-Energy Plano-Convex Lenses

High-energy lenses optimized for 355-nm offer very high transmission and damage thresholds, and standard fused silica lenses offer good performance and value over very broad spectral ranges.

High-Energy Spherical Lenses Fused Silica Spherical Lenses
Wavelength 355 nm 255-440 nm
Pulsed Damage Threshold 5 J/cm2 @ 20 ns, 10 Hz 2 J/cm2 @ 10 ns, 10 Hz
Average Reflectivity per Surface < 0.25% Ravg< 0.5%
Diameter 1 in. 0.25 to 2 in.
Substrate Material High Purity Fused Silica UV Fused Silica

UV High-Energy Polarizing Cube Beamsplitters

Optimized for 355-nm, these cubes offer high damage thresholds, efficient polarization, and high extinction ratio.

High-Energy UV Polarizing Cube Beamsplitters Laser Line Polarizing Cube Beamsplitters
Wavelength 355 nm 351-355 nm
Pulsed Damage Threshold 5 J/cm2 @ 10 ns (266 nm) 3 J/cm2 @ 10 ns, 10 Hz (266 nm)
Reflectivity Rs > 99%
Transmission Tp > 90%
Extinction Ratio Tp/Ts >200:1 Tp/Ts >100:1
Size 1 in. 0.5 to 1 in.
Substrate Material UV Grade Fused Silica

Zero-Order Waveplates (λ/4 and λ/2)

Very high damage threshold, low sensitivity to temperature and UV wavelength variation.

355 nm Zero-Order Waveplates
Wavelength 355 nm
CW Damage Threshold 2 MW/cm2
Reflectivity per Surface < 0.25%
Diameter 1 in.
Substrate Material Quartz
Temperature Coefficient 0.0001 λ/°C
Other Features ±λ/300 retardation accuracy

Opto-Mechanics

Criteria for Selecting Optical Mounts

  • Resolution/Sensitivity
  • Long Term Stability
  • Lockable
  • Size and Shape

Optical component mounts are needed to hold and adjust optics. Long term stability and low drift is crucial. Minimizing drift caused by vibrations or thermal drift over time will ensure laser alignment to the desired spot and also reduce any potential downtime due to misalignment and errors. Having a locking mechanism on these mounts can also prevent misalignment of the beam, especially during shipping and also if anything else happens during usage.

HVM industrial mounts are recommended for robust long term usage in compact space. The Suprema® mirror mount is excellent for its stainless steel construction that gives better thermal performance than an aluminum mirror mount. Ultra-fine 254-TPI adjusters provide alignment sensitivity as low as 1.5 arc sec. For applications that are really concerned about the thermal changes that can be potentially caused by prolonged high powered laser usage, the ZeroDrift™ version will compensate for some thermal changes as well. For those mirror mounts that need to be set-and-forget for a long period of time, we recommend the MFM flexure mirror Mount. These are excellent for their small footprint so that machine size can be reduced.

Suprema
Suprema
M-Series
M-Series
Optic Diameters 0.5, 1 and 2 in. 0.5, 1 and 2 in.
Resolution 50, 100, 127 and 254 TPI 100 TPI
Angular Range ±7° ±4°
Material Stainless Steel Aluminum
Drive Types Knob
Hex Key
Exchangeable Actuators
Knob
Hex Key
Lockable Versions Yes Yes
Other Versions Clear-Edge
Front- and Rear-Loading
Right- and Left-Handed
Low Wavefront Distortion
ZeroDrift™
Clear-Edge
Front- and Rear-Loading
Right- and Left-Handed
HVM-Series
HVM-Series
MFM-Series
MFM-Series
Optic Diameters 0.5, 1 and 2 in. 0.5, 0.75 and 1 in.
Resolution 80 and 100 TPI 80 and 100 TPI
Angular Range ±2.5°, ±3° and ±3.5° ±2.5°
Material Anodized Aluminum, Stainless Steel Stainless Steel
Drive Types Hex Key Hex Key
Lockable Versions Yes No
Other Features Front- and Rear-Loading Versions Shock Resistant
Front- and Rear-Loading Versions
Adhesive wells for permanent mounting
A-Line
A-Line
Compact
Compact
LP-Series
LP-Series
Optic Diameters 0.5 to 3 in. 1 in. 0.5, 1 and 2 in.
Resolution - 100 TPI 100 TPI
Adjustments Fixed XY, XYZ, XYZθxθy XY, XYZ, XYZθxθy
Material Aluminum Aluminum Aluminum
Other Features Self-aligning design
Large clear aperture
Compatible with A-Line alignment system
Adapters for other optics
Optional lock nuts
Zero-freeplay XY mechanism
True Gimbal adjustments
Independent non-influencing locks
Adapters for other optics
UGP-1
UGP-1
RSP-Series
RSP-Series
Optic Size 0.5 and 1 in. cube 1 and 2 in.
Resolution 100 TPI 4 arc min
Angular Range ±5° 360°
Material Aluminum Aluminum
Drive Types Knob w/ Hex Hole Coarse: knurled edge
Fine: knob
Lockable Yes Yes
Other Features True gimbal motion
Adapters for other optics
Full ball bearing races
Adapters for other optics
PX Post PX Pedestal
Diameter 1 in. 1 in. with 1.25 in. flange forkless-optical-pedestals
Heights 1, 2, 3 and 4 in.
Material Stainless Steel
Other Features Accessories for varying heights and mounting configurations

Laser Beam Analysis

Even with the advantages that lasers provide over traditional tools, lasers systems can degrade over time, leading to reduced output power or a change in focus. This, in turn, could result in lower quality laser operations, including sintering. Therefore, it is very important to monitor your laser beam frequently, and the critical parameters of the laser should be checked before and after each important step of the laser manufacturing process.

Causes of Laser System Degradation

  • Thermal Effects
  • Debris from Process
  • Vibrations and Shock
Figure 1. As the laser emerges from the laser source (left), it runs through a variety of laser delivery components, such as free-space optics and process fibers, which can change the power levels and beam profile (center). The laser beam next moves through the laser processing head. Mirrors and lenses and cover glass can also have a significant impact on power levels, size, and shape (right).

Criteria for Beam Analysis Instruments

There are three types of beam analysis instruments to monitor your laser: (1) sensors and detectors to measure power, (2) power meters to process the information provided by sensors and (3) beam profilers to determine focus position and other beam characteristics. Shown below are the main criteria for choosing such instruments.

Laser Sensors
  • Compatible with laser wavelength
  • Power/energy range/density
  • Beam size
  • Calibrated power measurement
Power Meters
  • Compatible with sensor
  • Connect to system/PC
  • Track process data over time
  • Compare multiple measurements at once
Beam Profilers
  • Measurement of multiple attributes
    • Focal shift
    • Focal spot size
    • Laser power and power density
    • Changes over time
    • Laser propagation characteristics
  • Speed of measurement

Thermal UV Power Sensors

Compact, fan-cooled UV sensors with high damage thresholds.

HVM-Series
FL250A-LP2-35
MFM-Series
F150(200)A-CM-16
Spectral Range 250 to 2200 nm 248 to 9400 nm
Power Range 0.1 to 250 W 0.3 to 200 W
Energy Range 0.5 to 300 J 0.05 to 200 J
Maximum Average Power Density 20 kW/cm2 35 kW/cm2
Maximum Energy Density (2 ms) 130 J/cm2 45 J/cm2
Aperture Ø35 mm Ø16 mm
Response Time 2 s 3 s
Application Long pulse lasers High rep rate lasers

Power Meters

Ophir laser power and energy meters work on the smart plug principle. This means that almost any power meter can work – plug and play – with almost any of the wide range of Ophir optical sensors.

Power Meters Virtual Power Meters
centauri
Centauri
StarBright
StarBright Handheld
Juno+
Juno+
EA-1
EA-1
  • Extensive graphic displays on 7-in full color touchscreen display
  • Advanced measurement processing
  • Single- or dual-channel versions
  • USB and RS-232 interfaces, with user-friendly software application
  • Analog and TTL output
  • External trigger input
  • Portable use
  • For transmission checks "in the field"
  • Variety of measurement modes and displays
  • USB & RS-232 interfaces
  • USB connection to use PC as monitor
  • User-friendly software
  • Extensive graphic displays of data
  • Advanced measurement processing
  • Data logging
  • Ethernet adapter enables remote control and monitoring of sensor
  • Telnet, HTTP and UDP protocols supported
  • Interact with sensor through custom software or MKS user-friendly software
  • Data logging

Beam Profilers

  • NanoScan™ Scanning Slit Beam Profiler: The most versatile laser beam profiler, providing instantaneous feedback of beam parameters for CW and kHz pulsed lasers.
  • SP932U Beam Profiling Camera: High resolution, real-time viewing and measuring of laser structure with highest accuracy in the industry.
NanoScan
NanoScan™
SP932U
SP932U
Spectral Range 190 to 1100 nm
Power Range µW to > kW
Damage Threshold 50W/cm2 / 1J/cm2 for < 100ns pulse width
Beam Sizes 7 µm – 3 mm or 20 µm – 6 mm 34.5 µm – 5.3 mm
Spatial Sampling Resolution 5.3 nm – 18.3 µm
Scan Frequency Up to 20 Hz
Pixels 2048 x 1536 Effective Pixels
3.45 µm Pixel Size
PC Interface USB 2.0 USB 3.0
Other Features Graphical user interface software included
M2 Wizard software for quick calculation
Integrated 200 mW power meter
BeamGage® software included
UltraCal™ correction algorithm
Measures cross-sectional intensity
72 dB true dynamic resolution
24 Hz frame rate in 12-bit mode

Motion Control

Galvanometer Scanners and Linear Positioners

Galvos
  • Advantages
    • Used to steer laser
    • Fast scanning (meters/sec) with sharp corners
  • Limitations
    • Limited field of view (~100-200 mm)
    • Limited focal spot size (10-20 µm)
Linear Positioners
  • Advantages
    • Used to position target or…
    • Used to position galvo(s)
    • Large field of view
    • Allows tight focal spots (<10 µm)
  • Limitations
    • Not as fast as galvos

Combined Galvo-Linear Positioners System

  • Combines speed of galvos with FOV allowed by positioners
  • Galvo and positioners can be synchronized with advanced motion controller
  • Enables "stitching":
    • Galvo process for "cells"
    • Positioners place next cell as target
    • Repeat galvo process
Galvos Linear Positioners Combined System
Speed & Acceleration Fast Not as fast Fast
Field of View (FOV) Limited Large Large
Focal Spot Size Limited Tighter Tight
  • MKS offers a full range of positioners and motion controllers
  • Galvos purchased separately – MKS controllers can interface with galvos

Guaranteed Motion Control Performance

  • Stages that MKS ships meet or exceed the guaranteed specifications
  • Metrology reports included with each stage (ASME B5.57 and ISO 230-2 standards)
  • Typically, the product will perform ~2x better than the guarantee

XM-S Series Linear Motor Stages

High sensitivity and outstanding trajectory accuracy in a compact, robust and cost-effective package.

XM-S Series
Travel Range 50 to 350 mm
Minimum Incremental Motion 1 nm
Speed 300 mm/s
Load Capacity 100 to 300 N
Accuracy ±0.2 to ±0.5 µm
Repeatability ±0.03 to ±0.035 µm
Straightness & Flatness ±0.37 to ±0.75 µrad
Other Features Ironless Linear Motor
Crossed-roller bearings

GTS-V Series High Precision Vertical Positioner

Highly accurate, repeatable and fast vertical motion in a compact unit

GTS-V Series
Travel Range 30 to 70 mm
Speed 5-10 m/sec
Load Capacity 40 to 70 N
Pitch ±0.25 to ±0.80 µrad
Roll ±0.25 to ±0.80 µrad
Accuracy ±0.75 to ±1.75 µm
Repeatability ±0.1 to ±0.5 µm
Other Features Direct vertical guiding system
Folded DC motor
Unobstructed access to payload

IMS Series Long-Travel Aluminum Linear Positioners

High load capacity, long travel, fast movement capable of high-duty cycles in industrial applications

Stepper Motor DC Motor
Travel Range 300 to 600 mm
Speed 100 m/sec 200 mm/sec
Load Capacity 600 N
Pitch ±37 to ±50 µrad
Yaw ±15 to ±30 µrad
Accuracy ±2.5 to ±4 µm
Other Features Double-row recirculating ball bearings
Linear motor version available

ILS Series Mid-Travel Aluminum Linear Positioners

High load capacity, mid-travel, fast movement capable of high-duty cycles in light industrial applications

Stepper Motor DC Motor
Travel Range 50 to 250 mm
Speed 50 m/sec 100 mm/sec
Load Capacity 250 N
Pitch ±15 to ±42 µrad
Yaw ±12 to ±25 µrad
Accuracy ±0.6 to ±1.7 µm
Other Features Double-row recirculating ball bearings
Linear motor version available

Motion Controllers

XPS-D
XPS-D
XPS-RLD
XPS-RLD
  • High performance, complex motion trajectories
  • Up to 8 axes
  • Extensive analog and digital I/O
  • Can synchronize galvos and positioners
  • Best for the most demanding applications
  • High performance, complex motion trajectories
  • Up to 4 axes
  • Analog and digital I/O
  • Can synchronize galvos and positioners
  • Good for demanding R&D and low volume production

Vibration Control

For applications that require holding alignments in place, we offer a comprehensive range of vibration isolation and damping solutions to ensure a stable system.

VC-MSG_MIG-S
Breadboards
VISION-325-S
Workstations
Integrity
Table Systems
VC-rs_series-S
Tables and Legs
Dimension Few feet Few feet Several feet, custom sizes Several feet, custom sizes
Thickness Few inches Few inches Several inches, custom thickness Several inches, custom thickness
Portability Must be carried or placed on "cart" Casters on legs are standard Larger, heavier, optional casters Larger, heavier, optional casters
Isolation None
Damping
Setup Base model comes assembled Base model comes assembled Support frame included but not assembled
May need help from riggers
Tables, legs sold separately
May need help from riggers